Biometric authentication systems are used for authenticating users of devices incorporating the authentication systems. Biometric sensing technology provides a reliable, non-intrusive way to verify individual identity for authentication purposes.
Fingerprints, like various other biometric characteristics, are based on unalterable personal characteristics and thus are a reliable mechanism to identify individuals. There are many potential applications for utilization of biometric and fingerprints sensors. For example, electronic fingerprint sensors may be used to provide access control in stationary applications, such as security checkpoints. Electronic fingerprint sensors may also be used to provide access control in portable applications, such as portable computers, personal data assistants (PDAs), cell phones, gaming devices, navigation devices, information appliances, data storage devices, and the like. Accordingly, some applications, in particularly portable applications, may require electronic fingerprint sensing systems that are compact, highly reliable, and inexpensive.
Biometric recognition typically involves comparing a match view to a stored enrollment template. When the match view is sufficiently similar to the stored enrollment template, they are considered a match and the biometric in the match view is recognized. It is possible for there to be one or several enrollment templates to check the match view against, and it is also possible for each enrollment template to have one or several views of the same biometric object (for example, corresponding to several partial views of the same fingerprint). Reducing the amount of data needed to store an enrollment template can provide several benefits. For example, limiting the amount of memory needed to store the enrollment template can save cost associated with memory and reduce size. Alternatively, allowing a given amount of memory to store more enrollment template data can improve the recognition process, for example, by allowing a greater number of partial views of a biometric to be stored, providing better coverage of the biometric pattern used in the recognition process. In addition, for increased security, it is often desirable to store the enrollment template locally, such as on the same local device, or even better on the same chip, used to capture the biometric match view and perform the recognition computations, so memory amount is often an important consideration in biometric recognition systems.
In view of the above, there is a need for compression techniques tailored to efficiently store various views of a biometric template. These and other advantages of the disclosure, as well as additional inventive features, will be apparent from the description of the disclosure provided herein.